Circuit Board Cavity Formation via Etching

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Solution Overview

Problem

Existing methods for forming cavities in circuit boards often result in contamination, increased processing time, and reduced yield due to carbonization and foreign particles, necessitating the development of a method that eliminates exterior processing and allows for precise control over cavity size and surface roughness.

Innovation Solution

A circuit board design featuring an insulation layer with a concave cavity and a via layer, where the via layer is exposed through the cavity bottom, and a manufacturing method involving the formation of a cavity pattern layer, conductive layers, and insulation layers, allowing for etching to create a cavity with uniform surface roughness and eliminating the need for exterior processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If exterior processing is used to form cavities, then cavity formation is achieved, but carbonization and foreign particles are generated causing substrate contamination and yield deterioration

Engineering Contradiction:

ImproveyieldVSAvoidcarbonization and foreign particles

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the cavity formation process from the exterior processing stage and integrates it into the circuit board manufacturing process. By forming cavities during the circuit board fabrication sequence rather than as a separate exterior process, the harmful carbonization and foreign particles are eliminated, thereby improving yield while maintaining cavity formation capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the cavity formation process with the circuit board manufacturing process. The cavity is formed by removing insulating material during the same processing sequence as circuit pattern formation, combining what were previously separate operations into a unified manufacturing flow, thus eliminating the need for separate exterior processing and associated contaminants

Inventive Principle:

Principle #5Merging (Combining)

2Productivity

If exterior processing is used to form cavities, then cavity formation is achieved, but processing time is increased due to additional desmear process

Engineering Contradiction:

Improveprocessing timeVSAvoidprocessing steps

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple processing steps into a unified manufacturing sequence. By forming cavities during the circuit board fabrication process rather than as a separate exterior process followed by a desmear process, the total processing time is reduced while maintaining the required cavity formation and surface quality

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent performs cavity formation during the initial circuit board manufacturing process rather than as a subsequent exterior process. This preliminary action eliminates the need for later desmear operations, thereby reducing overall processing time and simplifying the manufacturing sequence

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If conventional cavity formation methods are used, then cavities are formed, but size and height control precision is insufficient

Engineering Contradiction:

Improvecavity size and height controlVSAvoidcontrol difficulty

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies local quality control by forming cavities with specific dimensional characteristics at precise locations during the circuit board manufacturing process. The cavity size and height are controlled through localized removal of insulating material guided by circuit patterns, enabling precise control of cavity dimensions and their relationship to surrounding circuit structures

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent replaces mechanical exterior processing methods with a circuit-based manufacturing approach. By using circuit pattern formation and selective material removal during board fabrication, precise control over cavity dimensions is achieved through photolithography and etching processes rather than mechanical means, thereby improving manufacturing precision

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces the overall package thickness, eliminates exterior and desmearing processes, and decreases processing time while enabling precise control over cavity size and surface roughness, thereby enhancing yield and matching force.

Implementation Method 1

forming a cavity in the first insulation layer by etching the cavity pattern layer and the cavity conductive layer

Methodology Applied

Scientific EffectEtching:

Data Source

PatentUS20240284604A1Circuit board and method for manufacturing the same

Publication Date: 2024.08.22 SAMSUNG ELECTRO MECHANICS CO LTD

AI summary

Disclosed is a circuit board including: an insulation layer for burying at least one wire layer and at least one via layer and having a first side and a second side facing each other, and a first wire layer partly protruding over the first side of the insulation layer and partly buried in the insulation layer, wherein the insulation layer has a concave cavity dented from the first side, and part of the via layer is exposed from the insulation layer through a bottom side of the cavity.